21713601 has 16 divisors (see below), whose sum is σ = 35633024. Its totient is φ = 11453184.

The previous prime is 21713579. The next prime is 21713603. The reversal of 21713601 is 10631712.

It is not a de Polignac number, because 21713601 - 2⁷ = 21713473 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (21713603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39496 + ... + 40041.

It is an arithmetic number, because the mean of its divisors is an integer number (2227064).

Almost surely, 2^21713601 is an apocalyptic number.

21713601 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21713601 is a deficient number, since it is larger than the sum of its proper divisors (13919423).

21713601 is a wasteful number, since it uses less digits than its factorization.

21713601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79560.

The product of its (nonzero) digits is 252, while the sum is 21.

The square root of 21713601 is about 4659.7855100852. The cubic root of 21713601 is about 278.9827072696.

The spelling of 21713601 in words is "twenty-one million, seven hundred thirteen thousand, six hundred one".